Although introduced as a methodological tool for reaction time research, the time-accuracy operating characteristic appears to have great potential for making a substantive, as well as a procedural, contribution to experimental psychology. The two major parameters of the operating characteristic, the slope and intercept of the time-accuracy tradeoff region, may reflect different perceptual or motor processes and thus an examination of these parameters might allow previously undifferentiated processes to be investigated. Moreover, by contrasting the time-accuracy operating characteristics obtained when the subject controls his processing time with those obtained when the experimental controls the processing time, inferences can be drawn about the stages in the information processing sequence at which time-accuracy tradeoff mechanisms have their effect. Five experiments are proposed to investigate the determinants of the slope and intercept parameters of the time-accuracy function, and to identify where in the information-processing sequence the tradeoff mechanisms are localized.